Description from Flora of China
Shrublets or herbs. Stems glabrous, much branched. Leaves opposite, often fascicled, sessile or shortly petiolate, linear-oblanceolate to suborbicular, terete or with a shallow groove, fleshy, mucronate; stipules membranous. Inflorescence cymose; bracts membranous or leaflike. Flowers bisexual. Sepals 5, mucronate at apex. Petals absent. Stamens 10, 2-whorled, outer 5 staminodes, inner 5 opposite sepals. Pistil 3-carpellate. Ovary superior or ± sunken into the receptacle, 1-locular with single ovule. Style 1; stigma 3-fid. Fruit rupturing irregularly, enclosed in persistent calyx.
Ten species: from Macaronesia in the west to NW China and Mongolia in the east, with a center of diversity in tropical E Africa; one species in China.
(Authors: Lu Dequan; Mats Thulin)